Metallic glasses have developed from a state of scientific curiosity to industrial products such as brazing foils and magnetic flux conductors. Ferromagnetic metallic glasses have received much attention because of their exceptional ferromagnetic properties.
One limitation of metallic glasses is that the largest shapes that can be produced are thin ribbons. Ferromagnetic metallic glass materials exhibit unusually good magnetic properties; however, when bulk objects are formed by stacking the thin ribbons the thinness of the ribbons causes a low stacking efficiency which in turn causes a low apparent density. For magnetic applications this loss of apparent density results in an increase in volume of stacked ribbon that must be used to give the metallic glass properties comparable to conventional bulk products. In addition the thinness and flexibility of the metallic glass ribbons makes handling of products formed from stacked ribbons difficult.
The problem of forming bulk objects from thin amorphous ribbons has in part been overcome by U.S. Pat. No. 4,298,382 which teaches and claims placing finely dimensioned bodies in touching relationship with each other and then hot pressing with an applied force of at least 1000 psi (6895 kPa) in a non-oxidizing environment at temperatures ranging from about 25.degree. C. below the glass transition temperature to about 15.degree. C. above the glass transition temperature for a period of time sufficient to cause the bodies to flow and fuse together into an integral unit.
H. H. Liebermann in an article entitled "Warm-consolidation of Glassy Alloy Ribbon" points out that significant amounts of shear are required between adjacent ribbon for successful consolidation of amorphous materials.
The U.S. Pat. No. 4,298,382 patent and the Liebermann article establish a method for consolidation of amorphous material into a bulk product by promoting material flow. For many magnetic applications it is preferred to consolidate amorphous ribbon to, or near the theoretical density while minimizing material flow which causes loss of identity of the individual ribbons.